Arc depressing means for sealed relay



1969 E. SWIDERSKI 3,444,492

ARC DEPRESSING MEANS FOR SEALED RELAY Filed Jan. 4, 1967 IN Vl-INI ()R. EDWARD SWIDERSKI I %,j MJM his ATTORNEY-J" United States Patent 3 444 492 ARC DEPRESSING MEANS FOR SEALED RELAY Edward Swiderski, Hazlet, N.J., assignor to Wheelock Signals, Inc., Long Branch, N.J., a corporation of New Jersey Filed Jan. 4, 1967, Ser. No. 607,222 Int. Cl. H01h 9/30, 1/66, 51/28 U.S. Cl. 335201 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates to are depressing means for a sealed relay, and more particularly to an arc depressing means mounted externally of the sealed relay for producing a magnetic field in a plane passing between overlapping contacts of the relay.

Due to the tendency of conventional sealed relays to arc, their use is limited to applications in which low currents are to be utilized or where long life is not essential. The present invention has made it possible in a conventional sealed relay to use higher current and increase the life of the relay at rated loads.

The sealed relay structure of the present invention in its preferred form provides means for mounting a permanent magnet externally of the capsule with the poles of the permanent magnet lying in a plane which passes through the gap between the contacts, preferably at right angles to the magnetic flux which is generated between the contacts to actuate the relay.

For a more complete understanding of the present invention reference may be made to the detailed descriptiin which follows and to the accompanying drawings in w ich:

FIGURE 1 is a view in vertical section of a sealed relay assembly embodying the invention; and

FIGURE 2 is'a cross sectional view of the sealed relay taken along the line 2-2 of FIGURE 1 looking in the direction of the arrows.

The sealed relay structure shown in the drawings includes a spool-like frame or bobbin 10 having integrally formed legs 11 at both ends, a sealed glass capsule or envelope 12 accommodated within the hollow core of the frame or bobbin 10 and containing electrical contacts 13 and 14, an electrical winding 15 on the frame or bobbin 10, and external conductors 16 and 17 connected to the contacts 13 and 14, respectively.

The contacts are made of light weight resilient magnetic material, and the contacts are normally spaced apart or, that is to say, in open condition until they are closed by the energization of the winding 15. Upon energization of the winding 15 the contacts are magnetically attracted to each other, causing them to close and complete an electrical circuit between the conductors 1-6 and 17.

The sealed relay structure as thus far described is conventional, and for a more complete description of the structure and operation of this type of relay reference can -be made to the Russo Patent No. 3,167,625 issued Jan. 26, 1965.

The spool-like frame or bobbin 10 contains a semicircular slot surrounding the overlapping region of the contacts 13 and 14 to accommodate a semicircular permanent magnet 18. In the embodiment illustrated in the drawings, the inner surface of the permanent magnet 18 is of complementary shape to the outer surface of the sealed capsule or envelope 12. The pole faces 18a and 18b of the permanent magnet lie approximately in a plane which passes through the gap between the contacts 13 and 14, preferably at right angles to the magnetic flux which is generated between the contacts by the winding to close the contacts. The magnetic flux of the permanent magnet, schematically illustrated by the broken lines in FIGURE 2, produces a mechanical force which serves as an arc depressor in which the magnetic field exerts the same mechanical force on the arc plasma as on any conductor of the same dimension carrying the same current. The mechanical force which the magnetic field (intensity H) exerts on the arc plasma with the length l carrying current (I amps) is proportional to HIl. The plasma is bound by this magnetic force to the arc spots on the electrodes, thereby limiting the mobility of the are or causing the arc to assume a retrogressive motion under the influence of the magnetic field.

It is not essential that the region of overlap of the contacts and the location of the permanent magnet be midway between the ends of the sealed relay structure. The region of overlap and the location of the permanent magnet could be nearer one end than the other.

The invention has been shown in a single preferred form and by way of example only, and many modifications and variations can be made within the spirit of the invention. The invention, therefore, is not limited to any specified form or embodiment except insofar as such limitations are expressly set forth in the claims.

I claim:

1. A sealed relay structure comprising a sealed capsule containing overlapping electrical magnetic contacts, a

spool-like housing having a hollow core within which the capsule is accommodated, a winding on said spool-like housing, the energization and deenergization of said winding shifting the contacts from one position to another to open and close the relay, a permanent magnet partially surrounding the capsule at the overlapping region of the contacts, the opposite pole faces of the permanent magnet lying approximately in a plane which passes through the gap between the contacts, and an opening in the spoollike housing at the overlapping region of the contacts of substantially complementary shape with the permanent magnet for accommodating the permanent magnet on but exterior to the sealed capsule so that the permanent magnet can be placed on the sealed capsule while the latter is accommodated within the spool and before the winding is wound on the spool, the outer surface of the permanent magnet forming a portion of the spool on which the winding is wound.

2. A sealed relay structure as set forth in claim 1 in which the outer surface of the sealed capsule is substantially cylindrical and in which the shape of the permanent magnet is substantially semicircular.

References Cited UNITED STATES PATENTS 3,071,667 1/1963 Lee.

3,125,650 3/1964 Ellwood 335-151 3,166,652 1/1965 Werts 335-153 3,243,541 3/1966 De Falco 335-154 BERNARD A. GILHEANY, Primary Examiner.

D. M. MORGAN, Assistant Examiner.

U.S. Cl. X.R. 335-154 

